A New Design of Second and Third Harmonic Tuned Power Amplifier Based on Input Nonlinearity

This paper uses waveform analysis to discuss the conditions for the application of the second and third harmonic tuned power amplifier (HT
2,3
PA), based on the input nonlinearity characteristic of the device. Starting from the gate voltage with the second harmonic component, a current expression is found that satisfies the phase requirements of the HT
2,3
PA. It is found that the HT
2,3
PA can operate with high efficiency at Class B to Class A bias when the second and third harmonic impedance are open-circuited. To validate this method, a PA operating at 2.6 GHz is designed and fabricated using the CGH40010F transistor. The gain reaches 13.8 dB and the PAE is 76.5%, at the gate voltage of −1.81V and the input power of 28 dBm.